Certain devices (e.g., cameras, mobile telephones, etc.) use a flash device or unit (e.g., a flash light-emitting diode (LED)) that is driven by a converter circuit (e.g., a direct current (DC)/DC converter circuit). A constant current circuit keeps current provided through the flash LED at a constant. It is assumed that light intensity is proportional to the current provided through the flash LED. However, the constant current circuit consumes valuable space in such devices, and is expensive due to handling large currents.
The constant current circuit also causes a voltage drop, which consumes power and reduces efficiency. The voltage drop over the constant current circuit can be quite high since the constant current circuit is designed to work with both small currents (e.g., provided to autofocus lights, video lights, etc.) and large currents (e.g., provided to flash devices). Also, the spreading of component tolerances in the devices makes it difficult to lower the voltage drop. For example, in some devices, the current provided to the flash LED is one (1) ampere (A) maximum. The voltage drop over the constant current circuit in these devices is 0.5 volts (V), which means that 0.5 Watts (W) of energy is wasted as heat. In devices that include a flash LED with super capacitors, the current provided to the flash LED is ten (10) amperes (A), which means that five (5) Watts (W) of energy is wasted as heat.